1. Field of the Invention
The present invention relates to an image sensor, and more particularly, to an image sensor and related fabricating method thereof.
2. Description of the Prior Art
Digital cameras are electronic products being widely used nowadays, and image sensors are disposed in the digital cameras for converting lights into electric charges. Generally speaking, the conventional image sensors can be divided into two categories. One includes charge-coupled device (CCD) image sensors, and the other includes CMOS image sensors, wherein the CMOS image sensor is manufactured by using CMOS technology.
The CMOS image sensor can be manufactured by combining with its necessary peripheral circuits since it is manufactured by adopting a conventional CMOS circuit process, such that the manufacturing cost of the CMOS image sensor is much lower than that of the CCD image sensor. Except for the lower manufacturing cost, the CMOS image sensor also has advantages of a small size and low power consumption.
FIG. 1 is a diagram of a conventional CMOS image sensor 100 according to the prior art. In FIG. 1, the CMOS image sensor 100 includes a substrate 110 and a plurality of pixels within the substrate 110. Each pixel includes a sensing element 160, an optical filter 120, and a microlens 130. The microlens 130 is used for gathering an incident light 150. The optical filter 120 is disposed between the substrate 110 and the microlens 130, and utilized for filtering the incident light 150. As can be seen from FIG. 1, the incident light 150 needs to pass through the microlens 130 and the optical filter 120 to reach the sensing element 160. That is to say, the architecture of the conventional CMOS image sensor 100 will result in a loss of the incident light 150 before the incident light 150 finally arrives at sensing element 160. Additionally, the conventional CMOS image sensor 100 also has to enhance quantum efficiency and reduce cross-talk.
Hence, how to improve the performance of the CMOS image sensor and solve the abovementioned problem has become an important topic for designers in the field.